Spray head for swirling spray



April 21, 1964 E. H. GREEN 3,129,893

SPRAY HEAD FOR SWIRLING SPRAY Filed May 31, 1962 3 Sheets-Sheet 1 April 21, 1964 GREEN 3,129,893

' SPRAY HEAD FOR SWIRLING SPRAY Filed May 31, 1962 3 Sheets-Sheet 2 April 21, 1964 GREEN 3,129,893

SPRAY HEAD FOR SWIRLING SPRAY Filed May 51, 1962 3 Sheets-Sheet 5 a arrleus.

United States Patent SPRAY IEAD F912 SWIRHNG SPRAY Edward Howard (Green, 11 Army Trail, Addison, Ill. Filed May 31, 1962., Ser. No. 198,892 19 (Zlaims. (til. 239490) This invention relates generally to spray heads for use with containers intended to dispense certain products under pressure and more particularly is concerned with a spray head which is for producing a swirling spray.

Many materials have, in recent years, been packaged in comminuted, suspended or dissolved form in canisters, bottles and bombs and dispensed as desired through the use of valves and spray heads. The valves are of many different constructions and are mounted on the package or container, connected with a suitable spray tip, usually in push-button form. Depressing or tilting the spray tip or head will open the valve, and the material is forced out of a suitable orifice in the spray head.

Readily vaporizable products, such as liquid insecticides, hair spray, deodorizers and soluble materials are easily dispensed. Suitable carriers which are miscible with the vaporizable products or which are capable of dissolving the soluble materials are packed in the container along with a propellant, such as a compatible gas or Freon, and caused to pass through a simple orii e in the spray head. The expansion of the vapor or gas as it leaves the external orifice normally will provide a fine mist, giving the desired coverage or dispersion. Metering may be accomplished internally in the valve structure or externally at the discharge orifice.

Considerable difliculty has been experienced in attempting to dispense finely dispersed solids or viscous materials which are not capable of being vaporized. Such materials are carried by various liquids in the form of suspensions, emulsions and foams and often must be propelled by compressed air or gas which is compatible therewith. It will be appreciated that the expansion which occurs in the case of discharge of a vapor into the atmosphere at the discharge orifice will occur only to a small extent, if at all, in the case of such insoluble or non-vaporizable materials. Unless something is done to nebulize the material, causing it to pass through a simple orifice will result merely in creating a stream of liquid emerging from the spray head. Control and metering is required, even if it were possible to obtain a desired dispersion, and such control and metering has been unknown prior to this invention, at least in connection with the dispensing of these materials in a proper and desirable particle dispersion and pattern.

Included in these materials are waxes, starches, some heavy oils and the like. Even some paints may be included, although for the most part paints and enamels have been successfully dispensed from pressurized containers through the use of a valve mechanism which includes a spray tip having a depending stern provided with a slot at the bottom of the stem. This stem enters the socket of a valve member and the slot is placed in communication with the interior of the container as the valve member is unseated from the bottom surface of an annular gasket through which the stem extends. Such spray heads are provided with external discharge orifices of more or less conventional construction, but for the most part paints and enamels have the pigment materials finely ground and carried in volatile vehicles easily vaporized and carrying the paint particle with them. Although practically liquid when reaching the orifice, the paint and its carrier practically explode out of the discharge orifice due to the sudden expansion of the volatile carrier.

The materials of the non-vaporizable and insoluble type which are incapable of being carried by vaporizable vehicles present considerable problems in dispensation from pressurized packages. In addition to difficulty of nebulization, probably more trying a problem has been the obstacle of clogging. These materials, referred to hereinafter as heavy materials clog ordinary passageways primarily because of particles coming out of suspension or building up in corners and crevices because of inertia or centripetal force. They are normally forced out of the container in a mixture that is so thick or heavy as to be insufficient in and of itself to create a spray or nebulization for desired use.

It has been known for some time that a solution to either or both of these problems has been to create a rotation of the mixture in the spray head and as it emerged from the discharge orifice. This results in a so-called swirling spray, and, if capable of being produced with proper metering and control, will give the desired dispensing qualities.

The invention herein provides the solution to these problems by rapidly rotating the mixture as it passed through and out of the spray head, whereby to produce the swirling spray. Many known spray heads have been devised whose purpose has been to produce swirling sprays, but so far as known, these have not been successful in the dispensing of heavy materials with proper dispersion and control, and without having the passageways of the spray head clog and render the same useless.

Reference will be made herein to a pressurized mixture or to a propelled mixture. By this it is intended to mean the total of the material and vehicle with proellant, if any is occluded, that passes through the valve structure and through the spray head. These expressions are used as more generic than aerosol because this latter word infers a very fine vapor or gas, and properly would excluded heavy materials dispersed usually as fine droplets or particles. Such a propelled mixture for example might consist of a suspension of fine wax particles and an abrasive in a water vehicle with gas or compressed air to a small extent occluded in the water. Usually the propellant is in a gaseous state above the vehicle and heavy material and the mixture which is forced out has none of the propellant. A small quantity of propellant may be introduced directly through the valve to give added drive to the mixture passing to the spray head.

It is the primary object of the invention to provide a spray head which will be of a construction such as efficiently and continuously to nebulize pressurized mixtures including heavy materials in a swirling spray, overcoming the disadvantages mentioned above.

Still a further object of the invention is to provide a spray head for use with a pressurized container that enables the dispersion of pressurized mixtures carrying heavy materials, the said spray head being constructed of a minimum of simple and economically produced parts, easily assembled.

Still another object of the invention is to provide a spray head which will produce a discharge in the form of a swirling spray for the dispersion and nebulization of pressurized mixtures of heavy materials in which the spray head may readily be constructed to be associated with different constructions of valve mechanisms.

Many other objects of the invention will become apparent to those skilled in this art as the description thereof proceeds hereinafter, in connection with which preferred embodiments are illustrated in the attached drawings and explained in the specification.

In the drawings, the same characters of reference are used wherever feasible to designate the same or similar parts throughout the several figures thereof.

In the drawings:

FIG. 1 is a fragmentary front elevational view of a oneness pressurized container having a spray head constructed in accordance with the invention.

FIG. 2 is a similar view, but somewhat exploded, showing the insert out of engagement with the spray head.

FIG. 3 is a median sectional view through the spray head, with the insert poised in exploded relation thereto, the section through the insert being taken generally along the line 33 of FIG. and in the indicated direction.

FIG. 4 is an enlarged fragmentary sectional view taken through the spray head and valve structure of the containers of FIGS. 1 and 2, portions being shown in section.

FIG. 5 is a rear view looking into the insert, the flat face to be described being considered the front thereof.

FIG. 6 is a sectional view through the spray head insert taken generally along the line 6-6 of FIG. 5 and in the indicated direction.

FIG. 7 is a fragmentary sectional view of the spray ahead with the insert in permanent connection therewith taken generally along the line '77 of FIG. 4 and in the direction indicated.

FIG. 8 is a sectional view similar to that of FIG. 4 but on a reduced scale and illustrating a modified form of the invention.

FIG. 9 is a front-on elevational view of the spray head of FIG. 8 but with the insert removed.

The invention is characterized by the provision, in a spray head for use with a pressurized container for di pensing a pressurized mixture including a heavy material, of a horizontal post formed in the spray head coaxial with an annular cavity and having an insert or face piece engaged in the cavity upon the post and cooperating therewith to provide passageways leading to a first swirl chamber which gives an initial rotative motion to the propelled mixture. This chamber is called the swirl-forming chamber. From this chamber the rotating mixture passes to a second swirl chamber which smooths out or filters the rotative motion and discharges the same at a high velocity to the atmosphere by way of an externally opening orifice. The second chamber is called a swirl-smoothing chamber herein. The chambers and orifice are coaxial with the post. The post is provided with an extension thereof of reduced diameter that extends through the center of the swirl-forming chamber and part way into the swirl-smoothing chamber to define the inner face of the latter chamber and likewise to define the restricted entrance to the swirl-smoothing chamber.

Clogging of the passages of the spray head is probably most serious in the case of certain heavy materials which are dispensed at high rates. Waxes for polishing are included in such heavy materials. These deposit in crevices and corners and build up rapidly to block flow of the propelled mixture. The spray head of the inven tion is highly effective because it is practically nonclogging. Even if some of the dispensing passageways should become clogged, the construction according to the invention is such that the spray head will still operate with a symmetrical pattern, if at a somewhat reduced rate.)

In FIGS. 1 and 2 there is illustrated a spray head 10 constructed in accordance with the invention, here shown mounted upon a valve structure designated generally 12 (FIG. 4) that is carried within a pressurized container 14. The container 14 consists of a canister or bottle having a cover member 16 secured over the top thereof. The cover member 16 is of sheet metal suitably stamped and shaped to provide a central boss or pedestal formation 18 having a coaxial central aperture 20. An annular rubber gasket 22 is clamped in position inside of the pedestal formation 18 with its central opening 36 coaxial with the aperture 2'3. The valve structure 12 includes a valve plunger 13 that is normally biased upward by means of a coiled spring 24 contained within the valve housing 26. The upper flanged end 28 of the valve housing is crimped as at 30 to the bottom of the gasket 22. The valve member 13 is intended to ride up and down inside of the valve housing 26, and has a shoulder 34 formed on its upper end which engages the bottom of the gasket 22 about its central opening 36 in valve seating relationship.

The spray head it? has a depending stem 38 which slidingly and yet sealingly engages through the said central opening 36 of the gasket 22 in operating the valve structure. The bottom end of the stem is provided with an axially extending slot 44 that is open through the wall of the stem and extends upward into the gasket 22 a slight distance, short of the upper face of the gasket when the valve member is seated. The slot 40 may have a strengthening web formed therein as at 42.

The stem 38 is hollow, as shown, providing a central conduit 44. Thus, when the valve stem is pushed downward by the user pressing on the top of the spray head it), the shoulder 34 will be unseated from the bottom of the gasket 22 and access will be had for the propelled mixture coming up from the bottom of the container 14 by way of the dip tube as into the interior chamber 47 of the valve housing 2d. The mixture will pass up alongside of the valve member 13, past the shoulder 34 into the slot 4t) and up into the conduit 44 to be dispensed. It will be appreciated that the spray head 10 may be used with mixtures other than having heavy materials, and in such case the conduit 44- serves as an initial expansion chamber. Otherwise the mixture passing through the conduit will probably be in liquid condition. The arrows of FIG. 4 shows the path taken by the propelled mixture, although the valve is closed in this view and it should be understood that the unseating of the shoulder 34 is necessary before any material may be dispensed.

If desired, additional drive for the propelled mixture may be provided by introducing a small quantity of propellant to the chamber 47 by Way of a small opening 45.

As thus far described, the structure is known. The construction of the spray tip or spray head 10 comprises the essence of the invention.

The body 43 of the spray head 1% may have portions thereof hollowed out as at St to lighten the same and so as to minimize the amount of material needed to mold the same, but this is not essential. The conduit 44 continues well up into the head almost to the top thereof as shown at 52 and opens to a horizontally arranged elongate annular cavity 54 with which it communicates at the entrances 56 and 58. In comparison with the size of the external metering orifice which will be described, it is likely that only one of such entrances 56 and 58 will be needed, and hence, it is probably not necessary for the conduit 44 to continue as far as the point 52. Better distribution into the cavity 54 is achieved through the use of the two entrances, however.

The cavity 54- is formed by virtue of a central cylindrical post all integral with the spray head coaxial with the cavity 54, the said post 60 having a small cylindrical extension or projection 62 located at its outer end coaxial with the post 649. This extension or projection 62 is an important element of the invention and may take various forms. While shown integral with the post 60 and the post being shown integral with the head, these parts may be molded or formed separately and assembled to the head it It is most economical and preferable to mold the head with the post 6d and the projection 62 in a single step as an integral piece. The projection 62 is called a mandrel herein for reasons which will appear.

A cup-shaped piece or insert, as it will be mentioned hereinafter, is designated generally as 64, the same being frictionally engaged within the cavity 54, with the open end engaged upon the post 6%. The open end is considered the rear of the insert while the closed end is considered the front or face of the insert.

The insert 54 has a base wall 66 and an annular side wall 68 whose dimension in diameter is so related to the inner diameter of the cavity 54 as to form a tight fit in the cavity. During molding the cavity 54 may be provided with a very small annular bead 76 so that when the insert 64 is forced into position, the bead 70 will dig into the side wall 68 and through cold flow eventually permanently seat therein forming a very effective seal. Obviously the pressures of the propelled mixture might otherwise blow the insert 64 out of the cavity 54. The cavity 54 is slightly enlarged at 71 to facilitate entrance of the insert 64.

Attention is invited to FIGS. 3, 4, 5 and 6 which illustrate the insert. The base wall 66 of the insert has a blank or flat front face 72 with a center opening 74 that forms the exterior metering orifice. The mixture will be sprayed or nebulized out of this orifice 74. Coaxially with the external metering orifice 74 there are a pair of formations which, when associated with the extension or projection 62 will form the first chamber which is termed the swirl-forming chamber 76 and the second or swirl-smoothing chamber 73. The chamber 76 is shown here as generally square but has four tangential branches or channels as shown at 79, 86, 82 and 34. The chamber '78 is annular and communicates directly with the chamber 76. Both chambers 76 and 78 are formed in the base wall 66 during the molding of the insert 64.

The construction described gives rise to four triangular formations 86, 88, 90, and 92 at the bottom of the insert presenting flat transverse surfaces to the rear open end of the insert 64. The hypotenuses of these triangular formations are extended substantially throughout the length of the insert 64 in an axial direction, considering the axis of the external metering orifice 74 and the swirlsmoothing chamber 78 so that the resulting walls have a cross section somewhat like the chorded segments of a circle, and the overall cross-sectional configuration on the interior of the insert is square with slightly angled corners. The wall surfaces resulting from this structure are designated 94, 96, 98 and 160. At their outermost ends, these walls are flared outwardly producing chordsegment-shaped slanted surfaces 162, 104, 166 and 168. In addition to piloting the post 66 into the insert 64, the slanted surfaces present guiding surfaces to flow of propelled mixture. The chamfered edge 169 assists ready installation of the insert 64.

The post 60 is of an external diameter which is substantially the same as the distance across the flats of the square, that is the distance between opposite walls 94 and 98 for example. When the insert 64 is pressed into the cavity 54, therefore, there will be four irregularly shaped axial passageways such as those shown in FIG. 7 at 11%), 111, 112 and 113, each of such passageways being in direct communication with a respective one of the tangential grooves or channels 7h, 80, 82 and S4. The extension 62 passes fully through the chamber 76 and partially into the chamber 78. Propelled mixture entering the entrances 56 and 58 into the cavity 54 will be passed along the four irregularly shaped passageways 110, 111, 112 and 113 to the grooves '79, 8t), 82 and 84. It will be appreciated that these grooves will be covered or enclosed adjacent the chamber 76 by virtue of the end face 114 of the post 60 engaging upon and substantially overlying the triangular surfaces 86, 8%, 9i and 9?...

From an examination of FIG. 5, it will be appreciated that the propelled mixture will enter the swirl-forming chamber '76 at four points tangential to the chamber thereby causing a rotative movement of the propelled mixture within the chamber 76 in a counter-clockwise direction as shown by the arrows and at considerable speed because of the small volume of the chamber 76. This swirling will occur around the extension or projection 62. In effect this projection 62 is a swirl-forming mandrel and it promotes the swirl by providing a definite center about which the rotation is forced to occur. The pressure of continuously entering mixture will force the swirling mixture immediately to pass into the chamber 6 78 which is preferably smaller in volume. The mandrel 62 will define an annular entrance 116 (FIG. 4) to the chamber 78, and the swirl-smoothing chamber 78 itself is perfectly annular in configuration whereby a mechanical filtering or smoothing out of the swirl will occur. The speed of the swirl is increased because of the decreased size of the smoothing chamber 78 and therefore the material will be ejected through the external metering orifice 74 in a high speed swirl. This will result in a thorough dispersion and nebulizing the heavy material carried by the mixture.

It will be noted that the communication between the swirl-forming chamber and the swirl-smoothing chamber is at :116 which is an annular opening about the mandrel 62. It will therefore be seen that the discharge of the rotating mixture from the swirl-forming chamber occurs at locations radially spaced from the center of rotation of the swirl so that said mixture is introduced into the swirl-smoothing chamber at a considerable circumferential velocity. This is believed to be promoted by the existence of the mandrel, because the absence of the mandrel would result in a substantial quantity of mixture leaving at the center of the swirl-forming chamber in which case the actual circumferential velocity would be materially less.

It has been found that one or two of the grooves 79, 8t 82 and 84- may clog without preventing operation of the spray head 10. Under certain circumstances, clogging of all but one groove will not prevent operation. Due to the tangential entry of the aerosol from four different points, the elimination of one or more points does not prevent the others from exerting a twisting or swirling movement about the mandrel 62. It is believed that the mandrel prevents cross currents or turbulence which might equalize the rotative effect caused by the entering mixture. The non-symmetrical formation of swirling mixture in the swirl-forming chamber 76 will not be effective to prevent a swirling dispersion out of orifice 74 due to the smoothing and velocity-increasing action of the chamber 78.

It has been found that excellent metering control Without loss of efficiency of dispersion and nebulization may be achieved by varying the dimensions of the mandrel 62, the chamber 76, the chamber 73, and/or the external orifice 74.

The groove ends 79', 86', 82 and 84 are preferably rounded to eliminate pockets. Likewise the outer edge 66 of the post 61 is rounded to present smooth passage for the mixture carrying the heavy material.

The spray head 10 thus far described has a depending stem 38 and is suitable for use with a valve structure which is completely below the gasket 22. Such a spray head can readily be removed from the gasket and cleaned or replaced.

The invention, however, is not limited to this construction, which is designed for vertical reciprocation. It may be used in structures which are intended for tilting operation and combinations of tilting and reciprocating operation. Also other types of reciprocating valves may be used.

In the structure of FIGS. 8 and 9, the spray head is shown mounted on an assembly including a cover member 16 and valve structure 32. Note that the assembly is shown not associated with a canister or bottle. This is the form in which the structure is sold to packers of pressurized products, either with or without the spray head in place. The curled lip 16' with gasket compound 17 in place will be worked onto the container by the filler.

Spray head 150 differs from spray head 10 only in one respect. Instead of an integral stem 38, spray head 150 has a socket 152 and the valve structure 32' has an integral valve member 154 that has a lower plunger portion 13 and an upper tubular part 38. The tubular part 38 protrudes through the aperture 36 in gasket 22 as seen in FIG. 8 and presents a hollow stem above the pedestal 18. The center of the hollow bore 156 is closed at its lower end, and open at its top end. There are one or more transverse passages 158 at the bottom of the bore '15'6'adjacent the closed end which are normally externally blocked by gasket 22. Spring 24 riding in housing 26 pushes on the bottom of the plunger portion 13 to drive the shoulder 34- into valve seating engagement with the gasket 22. Pressing down on spray head 150 in turn pushes the valve member 154 down relatives to the gasket 22 carrying the passages 153 below the gasket to establish communication between the chamber 47 and bore 156. A small head in socket 152 (not shown) similar to head 70 may be used.

The insert 64- and post 64 are identical in construction and operation to those of the spray head 10.

It will be appreciated that given sufiicient clearance at 20 the hollow stem 38 may be tilted to cause dispensing of the mixture, although this structure is primarily intended for vertical reciprocation.

With respect to the materials from which the various components illustrated are formed, for the most part the valve structures are made of metal or plastic. As an example, valve housings such as 26 are of metal or plastic; the valve member 16 of FIG. 4 is usually of plastic; the valve member 15'4- of PEG. 8 is of plastic or metal; the gasket 22 is usually of rubber or synthetic rubber. The cover members .16 are most practically of sheet metal to permit easy forming in stamping machines and to enable crimping or other securement processes. The spray heads and 150 ad their inserts are preferably molded of plastic although the use of die cast metals or machined parts is not outside the scope of the invention. The greatest economy is achieved by the use of molded plastics.

With respect to the type of plastics used, care is required to choose a suitable composition which is at least fairly well compatible with the bases and propellants used in the mixture. Swelling and deterioration due to chemical or physical reaction may be insignificant with proper choice of plastics. Many synthetic resins are suitable.

The drawings are many times actual size, except perhaps for FIGS. 1 and 2. To give some idea as to the sizes of the components, several dimensions will suifice, and these are listed below, only by Way of example, subject to variation:

Inches Diameter of swirl-smoothing chamber 78 .050 Diameter of external metering orifice 74 .022 Axial length of swirl smoothing chamber overall,

disregarding mandrel 62 .020 Axial length of external metering orifice '74 .008 Distance across flats of wall faces 94, '96, 93 and 100 and diameter of post 60 .140 External diameter of insert '64 .225 Diameter of mandrel 62 .303

The other dimensions are more or less proportional to those given above.

Variations are readily made in the details or structure without departing from the spirit or scope of the invention. As examples of such variations, the swirl-forming chamber 76 and the tangential channels 759, 80, 82 and 84 could be made in such a manner that the channels spiral radially outward and the chamber '76 itself is more rounded so that the flow of the propelled mixture is smoother into the chamber. Dies to make such structures would be more difficult and expensive to make, but would operate in accordance with the theory of the invention. Likewise, the swirl-smoothing chamber 73 could be a continuation in an axial direction of the swirl-forming chamber 76 with the walls gradually tapering and with no sharp entrance corners, this being a result of more intricate detail in the molding cavities. In such case the mandrel 62 would not necessarily be cylindrical but might more effectively be tapered or follow in configuration the walls of the combined chambers, being suitably spaced therefrom to achieve the desired effects.

The structures which are illustrated and described herein are practical and relatively simple to make, keeping in mind the available tools and techniques of forming molding cavities. These structures produce the desired results very successfully, notwithstanding the presence of some sharp corners and turns required of the propelled mixture. It is expected that improvement would be made by the rounding of corners and the like.

What it is desired to secure by Letters Patent of the United States is:

l. A spray head for dispersion of a heavy material in a pressurized mixture and comprising a push button body member having a vertical conduit to be coupled to a source of said pressurized mixture, a plurality of passageways connected with said conduit and being circumferentially spaced about an axis which is at a substantial angle relative to said conduit and generally comprising the axis along which said spray head is adapted to discharge said mixture, 21 swirl-forming chamber in said body member, and each passageway having a feeder channel located outside of said swirl-forming chamber and leading into said chamber and each channel entering the swirl-forming chamber tangential thereof and at the periphery thereof, said chamber being perpendicular to and coaxial with said axis, and a discharge orifice axially spaced from said chamber and means in said chamber providing an annular communication between said chamber and said discharge orifice.

2. A spray head as claimed in claim 1 in which said means includes a swirl-smoothing chamber coaxial with said orifice and swirl-forming chamber and between them, and the volume of said swirl-smoothing chamber being less than that of said swirl-forming chamber.

3. A spray head as claimed in claim 2 in which said means further includes a mandrel in said swirl-forming chamber extending at least up to said swirl smoothing chamber and defining the entrance from said swirl-forming chamber to said swirl smoothing chamber.

4. A spray head, comprising a body having a vertical conduit adapted to be coupled to a source of pressurized mixture, a plurality of circumferentially arranged, generally horizontal passageways connected with said con duit and arranged to convey mixture away from said conduit, a first central swirl-forming chamber and each of said horizontal passageways connected with said chamber generally tangentially thereof so that pressurized mixture will be fed into said chamber in a rotating movement, a second chamber arranged coaxial with said first chamber and in communication therewith, a coaxial orifice in said second chamber leading to the exterior of said spray head, and a mandrel within said first chamber and extending therethrough and at least up to said second chamber to define an annular communication between said first and second chambers, the end of said mandrel being spaced axially from said orifice.

5. A spray head for pressurized mixtures and formed of two parts assembled together, one part comprising a push-button body and the other part comprising an insert, said body having a vertical conduit and means for coupling said conduit to a source of pressurized mixture, a horizontally arranged cylindrical Well in said body communicating at one end with the conduit and open at its second end to the exterior of the body, an elongate post integral with the body, coaxial with the well and of lesser diameter than the interior wall of said well whereby the post and well form an elongate cavity between them, said insert being cup-shaped with a cylindrical wall and a base Wall, the open end of the insert being inserted into the cavity and the outer surface of the cylindrical wall sealingly engaged with the cavity, the inner configuration of the cylindrical wall and the outer configuration of the post being incongruent but in engagement whereby to form a plurality of circumferentially arranged horizontal passage ways leading to the base wall of the insert on the interior thereof, a swirl-forming recess in the center of the base wall, the post end being seated on said base wall and covering said recess, channels formed by said post end and base wall between said passageways and recess entering said recess tangentially to cause rotative movement of the mixture therein, an externally opening discharge orifice in the base wall coaxial with the recess, and an annular chamber between the recess and orifice for passing the rotating mixture to the orifice.

6. A structure as claimed in claim in which said post has a central mandrel projecting through said swirl-forming recess.

7. A spray head for pressurized mixtures and comprising a body member having a vertical conduit adapted to be coupled to a source of pressurized mixture, a horizontally arranged annular cavity in the body member in communication with the conduit and defining a cylindrical post coaxial with the cavity, a cup-shaped insert engaged matingly in the cavity with the closed end outward and having a central discharge orifice, the outer side surface of the insert being sealed in the cavity, the inside of the insert having a polygonal cross section the flats of which are engaged with the outer surface of the post to form passageways leading from the cavity to the base of the insert, the post end being in engagement with the base, a swirl-forming recess in said base having its open face closed by the post end to form a swirl-forming chamber coaxial with the discharge orifice, the post end having a mandrel extending through said chamber and axially spaced from said discharge orifice, channels between the post end and base connecting the passageways with the swirl-forming chamber on a tangential entrance whereby to rotate the mixture entering the chamber, and an annular swirl-smoothing chamber in the base between the discharge orifice and the swirl-forming chamber for leading the rotating mixture to the discharge orifice.

8. A structure as claimed in claim 7 in which the mandrel extends at least partly into the swirl-smoothing chamber to define an annular entrance thereto from the swirlforrning chamber.

9. A spray head for dispersion of material carried by a pressurized mixture, said spray head adapted to be mounted upon a container holding said mixture under a high pressure and comprising: a body member having means for coupling the same to said mixture, a conduit in the body member connected with the coupling means, a swirl-forming chamber in the body member having a plurality or tangential feeding passageways connected with the conduit, a circular swirl-smoothing chamber immediately adjacent the swirl-forming chamber and somewhat smaller in diameter than the swirl-forming chamber, an external spray orifice leading out of the body member directly from the center of the swirl-smoothing chamber, and a central swirl-forming mandrel connected to the body member extending through the center of the swirli'orming chamber so that the swirl forms about the mandrel, and the mandrel extending at least up to the swirlsmoothing chamber and ending at a point spaced axially from said orifice so that the entrance to the swirl-smoothing chamber from the swirl-forming chamber is ring shaped.

10. A construction as claimed in claim 9 in which the body member has a cavity with a center post and there is a cup-shaped insert engaged in the cavity on the post, and in which the chambers, passageways and mandrel are provided by cooperative formations in the cavity and post, the orifice being in the center of the insert.

References Cited in the file of this patent UNITED STATES PATENTS 2,065,161 Van E. Thompson Dec. 22, 1936 2,138,300 Gustafsson Nov. 29, 1938 2,906,461 Bretz Sept. 29, 1959 2,962,228 Abplanalp et al Nov. 29, 1960 2,974,880 Stewart et a1 Mar. 14, 1961 3,033,473 Kitabayashi May 8, 1962 3,054,563 Steinen Sept. 18, 1962 3,064,865 Scoggin et al Nov. 20, 1962 FOREIGN PATENTS 275,233 Switzerland Aug. 1, 1951 920,117 Germany Nov. 11, 1954 973,108 France Sept. 6, 1950 

1. A SPRAY HEAD FOR DISPERSION OF A HEAVY MATERIAL IN A PRESSURIZED MIXTURE AND COMPRISING A PUSH BUTTON BODY MEMBER HAVING A VERTICAL CONDUIT TO BE COUPLED TO A SOURCE OF SAID PRESSURIZED MIXTURE, A PLURALITY OF PASSAGEWAYS CONNECTED WITH SAID CONDUIT AND BEING CIRCUMFERENTIALLY SPACED ABOUT AN AXIS WHICH IS AT A SUBSTANTIAL ANGLE RELATIVE TO SAID CONDUIT AND GENERALLY COMPRISING THE AXIS ALONG WHICH SAID SPRAY HEAD IS ADAPTED TO DISCHARGE SAID MIXTURE, A SWIRL-FORMING CHAMBER IN SAID BODY MEMBER, AND EACH PASSAGEWAY HAVING A FEEDER CHANNEL LOCATED OUTSIDE OF SAID SWIRL-FORMING CHAMBER AND LEADING INTO SAID CHAMBER AND EACH CHANNEL ENTERING THE SWIRL-FORMING CHAMBER TANGENTIAL THEREOF AND AT THE PERIPHERY THEREOF, SAID CHAMBER BEING PERPENDICULAR TO AND COAXIAL WITH SAID AXIS, AND A DISCHARGE ORIFICE AXIALLY SPACED FROM SAID CHAMBER AND MEANS IN SAID CHAMBER 